This disclosure relates to fabrication of thin film photovoltaic solar cells.
Solar cells are electrical devices for generation of electrical current from sunlight by the photovoltaic (PV) effect. Thin film solar cells have one or more layers of thin films of PV materials deposited on a substrate. The film thickness of the PV materials can be on the order of nanometers or micrometers.
Examples of thin film PV materials used as absorber layers in solar cells include copper indium gallium selenide (CIGS) and cadmium telluride. Absorber layers absorb light for conversion into electrical current. Solar cells also include front and back contact layers to assist in light trapping and photo-current extraction and to provide electrical contacts for the solar cell. Many solar cells also include buffer layers as intermediate layers between the absorber and front contact layers to improve layer interface properties and protect the absorber during further processing. However, some commonly-used processes for deposition of thin films result in damage to the thin film substructures.